What makes a home varies wildly around the world. From a small apartment in the heart of Dubai, to a hut in the steppes of Mongolia, to two-story prefab on a quarter-acre lot in Phoenix, houses come in many shapes and sizes. On occasion, they also come in monster size. While every person's home is his or her castle, sometimes we still can't help but gawk at someone else's really large, really expensive house. It's in this spirit that we get to the bottom of just who has the most expensive home in the world? Experts of Insidermonkey settled the issue here, taking a glimpse at the most expensive real estate in the world.

If you have $437 million lying around and don't know how to spend it, why not try to scoop up a 60,000 square foot property in one of London's most chic neighborhoods? That's a few hundred thousand dollars above a reported bid of £280 million ($436.5 million) for a London mansion that has been empty for three years. If the bid goes through, it would become the UK's most expensive home sale ever. Despite the big ticket and splashy sale, the home is only the fourth most expensive in the world. So, how much would you pay to live in a lavish palace appointed with the most luxurious furniture and fixings? There are homes that would stretch any budget, even if you're among the super rich.

Though, it’s obvious that the real estate on this list won’t be found in any of the 20 countries with lowest cost of living, which we covered in a previous article. However, some of the off-trail sites may leave you wondering why someone would want to live there (and at such an exorbitant cost). While some of these houses, penthouse suites, and castles are inhabited, others are used for mere investment purposes.